Transferring apparatus of color laser printer

Abstract

An apparatus to transfer a color laser image including an intermediate transfer belt around a plurality of guide rollers provided in a printer body frame; a transfer roller to contact the intermediate transfer belt with a transfer nip, and to transfer the color image of the intermediate transfer belt to a printing paper; a transfer panel, positioned to open and close with respect to the printer body frame, to support the transfer roller; a separating unit to separate the transfer roller from the intermediate transfer belt at constant intervals or pressurize the transfer roller to contact the intermediate transfer belt; and an aligning unit to align the transfer roller with respect to the intermediate transfer belt in the printer body frame. The positions of the central axis of the intermediate transfer belt and the axis of the transfer roller are controlled at the same level on the printer body frame.

1. An apparatus to transfer a color image in a laser printer, comprising:
 a printer body frame having a side wall;  
 a plurality of guide rollers provided in the printer body frame;  
 an intermediate transfer belt to rotatably travel along a loop by being wound around the guide rollers, and to transfer the color image by a toner;  
 a photosensitive drum, the intermediate transfer belt receiving the color image from the photosensitive drum;  
 a transfer roller to press and contact the intermediate transfer belt with a transfer nip therebetween, and to rotate to transfer the color image of the intermediate transfer belt to a printing paper;  
 a transfer panel, positioned to rotatably open and close with respect to the printer body frame, to support the transfer roller to be rotatable;  
 a separating unit to separate the transfer roller from the intermediate transfer belt at constant intervals or to press the transfer roller to contact the intermediate transfer belt; and  
 an aligning unit to align the transfer roller to maintain an accurate position of the transfer roller with respect to the intermediate transfer belt in the printer body frame.  
 
   
   
     2. The apparatus according to  claim 1 , wherein the aligning unit comprises:
 a guide axis being parallel and connected to the transfer roller at predetermined intervals and including a plurality of projection guide portions being projected on sides of the transfer roller,  
 the side wall inward of the printer body frame to receivably support the projection guide portions of the guide axis.  
 
   
   
     3. The apparatus according to  claim 2 , wherein the separating unit comprises:
 first and second pressurizing blocks, being supported by the transfer panel, the pressurizing blocks each comprising: 
 a first axis hole to support the transfer roller and having an open side to receive the transfer roller, and  
 a second axis hole into which the guide axis is inserted;  
 
 first and second separating levers, being respectively connected to the first and second pressurizing blocks and extending outward from the first and second pressurizing blocks, the separating levers having ends which are disposed to be engaged to the projection guide portions of the guide axis;  
 a cam operation part formed at an end of the second separating lever;  
 first and second elastic members being respectively provided between the first and second pressurizing blocks and the transfer panel to elastically support the first and second pressurizing blocks in a direction in which the transfer roller is pressed against the intermediate transfer belt; and  
 a cam unit to rotate the second separating lever in a direction in which the transfer roller is separated from the intermediate transfer belt, the cam unit including a cam provided in the side wall of the printer body frame to be connected to the cam operation part of the second separating lever.  
 
   
   
     4. The apparatus according to  claim 3 , wherein the first and second pressurizing blocks further comprise hook holes formed therein, and the first and second separating levers comprise hooks, and the first and second pressurizing blocks and the first and second separating levers are connected to each other by inserting the hooks into the hook holes. 
   
   
     5. The apparatus according to  claim 4 , wherein the aligning unit further comprises:
 guide members being provided on an inside of the printer body frame to receivably support the projection guide portions of the guide axis.  
 
   
   
     6. An apparatus to transfer an image to a medium, comprising:
 a frame having a side wall;  
 a belt to receive the image;  
 a roller to selectively be separate from the belt and selectively press against the belt with a nip formed therebetween, and to transfer the image from the belt to the medium; and  
 an aligning unit, attached to the side wall of the frame, to align the roller relative to the belt when the roller is seperate from the belt and when the roller presses against the belt.  
 
   
   
     7. An apparatus to transfer an image to a medium, comprising:
 a frame having a side wall;  
 a belt to receive the image;  
 a roller to press against the belt with a nip formed therebetween, and to transfer the image from the belt to the medium;  
 an aligning unit, attached to the side wall of the frame, to align the roller relative to the belt; and  
 a moving unit to selectively separate the roller from the belt and press the roller against the belt, the moving unit comprising: 
 a cam attached to the side wall of the frame, and  
 a lever to move as a result of a rotation of the cam and thereby move the roller from/against the belt, the lever having an end.  
 
 
   
   
     8. The apparatus according to  claim 7 , wherein the aligning unit comprises:
 a guide axis connected to the roller and comprising a projection to engage with the end of the lever and thereby receive the movement of the lever; and  
 a guide member, on the side wall of the frame, to support the projection.  
 
   
   
     9. The apparatus according to  claim 8 , further comprising:
 an opening/closing unit to support the roller and selectively open/close with respect to the frame, wherein an alignment of the roller with respect to the belt is constant between successive closed states of the opening/closing unit.  
 
   
   
     10. An apparatus to transfer an image to a medium, comprising:
 a frame having a side wall;  
 a belt to receive the image;  
 a roller to press against the belt with a nip formed therebetween, and to transfer the image from the belt to the medium; and  
 an opening/closing unit to support the roller and selectively open/close with respect to the frame, wherein an alignment of the roller with respect to the belt is maintained during open and closed states of the opening/closing unit.  
 
   
   
     11. The apparatus according to  claim 10 , further comprising:
 an aligning unit, attached to the side wall of the frame, to align the roller relative to the belt.  
 
   
   
     12. The apparatus according to  claim 11 , wherein the aligning unit comprises a substantially linear element bent upon itself to form a V-shaped groove to receive the roller and align the roller relative to the belt.